At a glance: facts about emergency contraception

You need to take the emergency contraceptive pill within 3 days (Levonelle) or 5 days (ellaOne) of unprotected sex for it to be effective – the sooner you take it, the more effective it'll be.

The IUD can be fitted up to 5 days after unprotected sex, or up to 5 days after the earliest time you could have ovulated, for it to be effective.

The IUD is more effective than the contraceptive pill at preventing pregnancy – less than 1% of women who use the IUD get pregnant.

Taking the emergency contraceptive pills Levonelle or ellaOne can give you a headache or tummy pain and make you feel or be sick.

The emergency contraceptive pill can make your next period earlier, later or more painful than usual.

If you're sick (vomit) within 2 hours of taking Levonelle or 3 hours of taking ellaOne, go to your GP, pharmacist or genitourinary medicine (GUM) clinic, as you'll need to take another dose or have an IUD fitted.

If you use the IUD as emergency contraception, it can be left in and used as your regular contraceptive method.

If you use the IUD as a regular method of contraception, it can make your periods longer, heavier or more painful.

You may feel some discomfort when the IUD is put in, but painkillers can help.

There are no serious side effects of using emergency contraception.

Emergency contraception doesn't cause an abortion.

How the emergency pill works

Levonelle

Levonelle contains levonorgestrel, a synthetic (man-made) version of the natural hormone progesterone produced by the ovaries.

Taking it's thought to stop or delay the release of an egg (ovulation).

Levonelle has to be taken within 72 hours (3 days) of sex to prevent pregnancy. It doesn't interfere with your regular method of contraception.

ellaOne

ellaOne contains ulipristal acetate, which stops progesterone working normally. This also works by stopping or delaying the release of an egg.

ellaOne has to be taken within 120 hours (5 days) of sex to prevent pregnancy.

If you take Levonelle or ellaOne

Levonelle and ellaOne don't continue to protect you against pregnancy – if you have unprotected sex at any time after taking the emergency pill, you can become pregnant.

They aren't intended to be used as a regular form of contraception. But you can use emergency contraception more than once in a menstrual cycle if you need to.

Who can use the emergency pill?

Most women can use the emergency contraceptive pill. This includes women who can't use hormonal contraception, such as the combined pill and contraceptive patch. Girls under 16 years old can also use it.

But you may not be able to take the emergency contraceptive pill if you're allergic to anything in it, have severe asthma or take any medicines that may interact with it, such as:

Buying it

If you're aged 16 or over, you can buy the emergency contraceptive pill from most pharmacies, in person or online, and from some organisations, such as the British Pregnancy Advisory Service (BPAS) or Marie Stopes. The cost varies, but it will be around £25 to £35.

Contraception for the future

If you're not using a regular method of contraception, you might consider doing so to protect yourself from an unintended pregnancy.

There are several methods of contraception that protect you for a long period, so you don't have to think about them once they're in place, or remember to use or take them every day or every time you have sex.

See a GP, nurse or visit your nearest sexual health clinic to discuss the options available.

If you're under 16 years old

Contraception services are free and confidential, including for people under the age of 16.

If you're under 16 and want contraception, the doctor, nurse or pharmacist won't tell your parents (or carer) as long as they believe you fully understand the information you're given, and the decisions you're making.

Doctors and nurses work under strict guidelines when dealing with people under 16. They'll encourage you to consider telling your parents, but they won't make you.

The only time a professional might want to tell someone else is if they believe you're at risk of harm, such as abuse. The risk would need to be serious, and they would usually discuss this with you first.